【作者】 滕春凯； 尹祥础； 李世愚； 蔡戴恩；

【Author】 Teng Chunkai (Institute of Geophysics,Chinese Academy of Sciences) Yin Xiangchu Li Shiyu Cai Daien (Institute of Geophysics,State Seismological Bureau)

【机构】 中国科学院地球物理研究所； 国家地震局地球物理研究所；

【摘要】 在研究地震孕育及震源破裂的问题时,用三维破裂来模拟地震破裂过程,比二维破裂与实际更加接近.我们设计了一组实验,采用几组不同的材料(玻璃、有机玻璃和大理石等)做成平板试件,在其中心预制非穿透裂纹,并在单轴压下进行了实验研究.实验结果表明,非穿透裂纹与穿透裂纹的扩展情况有质的区别.非穿透裂纹的扩展并不沿原裂纹面延伸,而是沿裂纹前缘扩展出许多裂纹面,每一个裂纹面都是复杂的扭曲、拐折的曲面.这可能意味着实际地震断层的扩展情况也是极为复杂的.更多还原

【Abstract】 Since seismic faults rarely penetrate through the lithosphere,three dimensional model of seismic fracture process is a better approximation than two dimensional one in studying preparation and rupture process of earthquakes.In order to compare these two models,a set of fracture experiments have been carried out for plate specimens of several kinds of materials(glass, plexiglass,marble etc.) with pre-existing non-penetrating crack oblique to the loading axis. The experimental results show that growth of a non-penetrating crack is essentially different from the penetrating one.The process of a non-penetrating crack has some mean features as follows:(a) Many small cracks with equal intervals approximately arise along the whole crack front.The small cracks enter into alignment with each other and become larger and fewer.(b) They are likely screw-symmetric about the original crack.(c) Each of such cracks is a very complicated surface in 3-D space.All of these suggest that the rupture process of an earthquake is much more complicated than the present models of seismic source.更多还原